1. Field of the Invention
The present invention relates to a flat panel display. More particularly, the present invention relates to a flat panel display which is not influenced by RC delay.
2. Description of Related Art
A conventional display panel includes a plurality of pixels arranged in an array. However, if parasitic resistance and parasitic capacitance of each pixel is simplified as a first-order low-pass filter circuit with an equivalent resistor and an equivalent capacitor, a scan line coupled to a plurality of the pixels then may be regarded as a series of low-pass filters. Therefore, when an enabled scan signal passes through the low-pass filters, a high-frequency signal may be gradually declined, such that waveform of the scan signal transmitted to the final low-pass filter may be different from that transmitted to the first low-pass filter.
FIG. 1 is a waveform diagram of a conventional scan signal. When scan signals V1 and V2 are input to a display panel, waveforms of the scan signals V1 and V2 may be as that shown in FIG. 1(a); and when scan signals V1′ and V2′ are output from the display panel, the waveforms of the scan signals V1′ and V2′ may be as that shown in FIG. 1(b). In FIG. 1(a), the scan signals V1 and V2 are not influenced by RC delay, and rising edges and falling edges of the scan signals V1 and V2 are transient.
Referring to FIG. 1(b), it is obvious that the scan signals V1′ and V2′ all have the RC delay, especially the falling edges of the scan signals V1′ and V2′ are obviously prolonged. Moreover, during a time interval of t2, since the scan signals V1′ and V2′ are influenced by the RC delay, the scan signals V1′ and V2′ are both enabled.
FIG. 2 is a waveform diagram illustrating a conventional method of intervening scan signals with a control signal. Referring to FIG. 2, to solve the above problem, a control signal OE is provided, and is used for intervening the rising edge and the falling edge of the scan signals of two adjacent rows. When the control signal OE is enabled, each of the scan signals has a low voltage level, and therefore enable time of the control signal OE is important. If the enable time of the control signal OE is too short, the scan signals are then influenced by the RC delay, such that the scan signals of the two adjacent rows may be simultaneously enabled, which may cause a problem that data may be repeatedly written on the pixels. When the enable time of the control signal OE is too long, though repeat writing of data on the pixels is avoided, charging time of the scan line is wasted, which may cause insufficient charging of the pixels.